Instrumentations

Control Valve Accessories

Control Valve Accessories

Basic, Instrumentations 31 Tháng Bảy, 2014 at 8:44 sáng

Positioners Pneumatically operated valves depend on a positioner to take an input signal from a process controller and convert it to valve travel. These instruments are available in three configurations: 1. Pneumatic Positioners—A pneumatic signal (usually 3-15 psig) is supplied to the positioner. The positioner translates this to a required valve position and supplies the valve actuator with the requiredRead More

Valve Actuators

Valve Actuators

Basic, Instrumentations, Mechanical, Technology 24 Tháng Sáu, 2014 at 4:59 chiều

Introduction Through themselves, valves cannot control a process. Manual valves need an operator to position them to control a process variable. Valves that must be operated remotely and automatically need special devices to move them. These devices are known as actuators. Types of actuators include manual handwheel, manual lever, electrical motor, pneumatic, solenoid, hydraulic piston, and self-actuated. All actuators exceptRead More

Types of the valve

Types of the valve

Basic, Instrumentations, Mechanical, Technology 23 Tháng Sáu, 2014 at 6:32 chiều

This tutorial briefly describes the basic components of different types of linear and rotary action control valves available for use in steam and water systems. A basic control system would normally consist of the following components: Hướng dẫn này mô tả các thành phần cơ bản và sự khác nhau của các van điều khiển kiểu tịnh tiến và kiểuRead More

pH Measurement

pH Measurement

Basic, Instrumentations 23 Tháng Sáu, 2014 at 6:08 chiều

pH measurement has a wide variety of industrial applications in virtually every industry. These range from water conditioning to specific process related measurements to waste treatment. Bài viết này sẽ giới thiệu sơ lược về phương pháp điện hóa là phương pháp sử dụng công cụ mà chuyển đổi đại lượng pH (độ hoạt động của ion H+) thành tínRead More

Filling material level measurement.

Filling material level measurement.

Basic, Instrumentations 23 Tháng Sáu, 2014 at 5:57 chiều

The “classical approach” to measuring the filling level With ball mills this working point is linked directly to the level of the material being ground in the mill. A mill that is too empty, i.e. one that has been underfed, operates extremely uneconomically from the energy point of view while a mill that is too full, i.e. has been overfed,Read More

Ultrasonic Level Measurement

Ultrasonic Level Measurement

Basic, Instrumentations 23 Tháng Sáu, 2014 at 5:53 chiều

Ultrasonic level instruments operate on the basic principle of using sound waves to determine liquid/ solid/slurries level. In addition to standard level or volume measurement, they can monitor open channel flow, determine the actual volumetric throughput in lift stations, measure differential level and control the pumps. Ultrasonic Level Transmitters consist of two elements; 1) a high efficiency transducer and, 2)Read More

Pitot Tube Flow Detectors

Pitot Tube Flow Detectors

Basic, Instrumentations 23 Tháng Sáu, 2014 at 5:50 chiều

The pitot tube, illustrated in Figure 5, is another primary flow element used to produce a differential pressure for flow detection. In its simplest form, it consists of a tube with an opening at the end. The small hole in the end is positioned such that it faces the flowing fluid. The velocity of the fluid at the opening ofRead More

Venturi & Dall Tube Flow Detectors

Venturi & Dall Tube Flow Detectors

Basic, Instrumentations 23 Tháng Sáu, 2014 at 5:46 chiều

HEAD FLOW METERS Flow measurement is an important process measurement to be considered in operating a facility’s fluid systems. For efficient and economic operation of these fluid systems, flow measurement is necessary. Head flow meters operate on the principle of placing a restriction in the line to cause a differential pressure head. The differential pressure, which is caused by theRead More

Orifice Plate Flow Detectors

Orifice Plate Flow Detectors

Basic, Instrumentations 23 Tháng Sáu, 2014 at 5:43 chiều

HEAD FLOW METERS Flow measurement is an important process measurement to be considered in operating a facility’s fluid systems. For efficient and economic operation of these fluid systems, flow measurement is necessary. Head flow meters operate on the principle of placing a restriction in the line to cause a differential pressure head. The differential pressure, which is caused by theRead More

Differential Pressure Level Detectors

Differential Pressure Level Detectors

Basic, Instrumentations 23 Tháng Sáu, 2014 at 5:13 chiều

The differential pressure (ΔP) detector method of liquid level measurement uses a ΔP detector connected to the bottom of the tank being monitored. The higher pressure, caused by the fluid in the tank, is compared to a lower reference pressure (usually atmospheric). This comparison takes place in the ΔP detector. Figure 9 illustrates a typical differential pressure detector attached toRead More